Providing relative translation without rotation

Abstract

A device may include a first plate and a second plate, and a linkage system that attaches the first plate and the second plate to one another such that the plates are capable of translating relative to each other, and the plates are incapable of rotating relative to each other.

1. A device comprising
 a first plate and a second plate; and 
 a linkage system comprising at least three rods, each having a first end and a second end; 
 wherein:
 the first ends of the rods are attached to the first plate, each by a universal joint; 
 the second ends of the rods are attached to the second plate, each by a universal joint; 
 the rods are arranged such that they are:
 parallel to one another; and 
 do not all lie in one plane; 
 
 the universal joints attaching the first plate to the first ends of the rods lie in a first plane; and 
 the universal joints attaching the second plate to the second ends of the rods lie in a second plane parallel to the first plane; 
 
 such that:
 the first plate and the second plate are capable of translating relative to each other; and 
 the first plate and the second plate are incapable of rotating relative to each other. 
 
 
     
     
       2. The device of  claim 1  further comprising a first platform attached to the first plate and a second platform attached to the second plate. 
     
     
       3. The device of  claim 2  wherein the first plate and the first platform are integrally formed, and the second plate and the second platform are integrally formed. 
     
     
       4. The device of  claim 2  wherein the plates are parallel to one another. 
     
     
       5. The device of  claim 1  wherein each plate is configured to receive a shoe, each shoe being so sized and shaped as to conform to a human foot. 
     
     
       6. The device of  claim 5  wherein each shoe can be rotationally and translationally fixed relative to the plate configured to receive the shoe. 
     
     
       7. The device of  claim 1  wherein the three rods are adjustable in length. 
     
     
       8. The device of  claim 7  wherein the three rods are capable of assuming a locked state and an unlocked state;
 where in the locked state the lengths of the rods cannot be adjusted; and 
 where in the unlocked state, the lengths of the rods can be adjusted. 
 
     
     
       9. The device of  claim 1 , further comprising at least one motor actuating at least one joint. 
     
     
       10. The device of  claim 9 , further comprising at least one sensor monitoring position, angle, or torque of a joint. 
     
     
       11. The device of  claim 10 , further comprising a control system that receives input from the sensor and actuates the motor. 
     
     
       12. The device of  claim 1 , wherein a point on the first plate remains at a fixed distance from a point on the second plate in all permitted translations. 
     
     
       13. A method of treating clubfoot in a patient comprising seating the patient's feet in shoes attached to the device of  claim 6 .